Answer:
Ethanol most easily forms hydrogen bonds.
Explanation:
The difference among the alcohols in this question is the size of carbonic chain and the position of the -OH group.
Ethanol has 2 carbons and the -OH group is terminal. The other alcohols have more carbons and the -OH group is not terminal. This means that the approximation of molecules will be facilitated for ethanol, and the interaction through hydrogen bons will be easier. However, for the other molecules, there will be steric hindrance, which will make it more difficult for the molecules to make hydrogen bonds.
The figure attached shows the alcohol structures.
